Which JavaScript function should you use?

You develop a webpage that allows a user to download a JPEG image and convert it to a PNG file.
You need to implement the code to download the contents of the JPEG image with no additional decoding.
Which JavaScript function should you use?

A.
readAsBinaryString()

B.
readAsArrayBuffer()

C.
readAsDataURL()

D.
readAsText()

Explanation:
The readAsArrayBuffer method is used to read a File, Blob, MSStream into memory as an ArrayBuffer object.
FileReader.readAsArrayBuffer